The Case of the Missing Machines

It began as a simple customer request. My company, the aerospace supplier Bertsche, was working with a tier-one manufacturer of large airplane structural assemblies. It needed to modify semi-finished and partially-assembled detail parts on a daily basis.

The parts are needed for large airplane structural assemblies, and they need to be in place just prior to final assembly. The manufacturer was searching for an all-purpose machine that could quickly be step up to run a wide variety of parts to support several different airplanes. It was using three older machining centers, and there were production and logistical problems.

Airplane manufacturers often start the manufacture of parts for a specific airplane order well before all detail parts for that airplane have been fully defined. This is great for the airlines, but it complicates the process of building planes on a tight schedule. Furthermore, airplane manufacturers must have considerable flexibility built into their processes, to allow last-minute modification to parts that will be needed shortly in final assembly.

The manufacturer needs to modify or rework every detail part for a specific structural assembly. On short notice, CNC (computer numerical control) part programs need to be created for virtually every part used in the subassembly, while special tools and fixtures need to be available and easily set up in machines. Thus, the parts must be manufactured just before they are needed at assembly. This is truly a “one off” manufacturing environment where the first part must be a good part with no margin for error.

The customer’s initial request was simple: replace three small footprint machining centers with a single machine tool that could quickly reconfigure tools, workholding fixtures, and programs to manufacture the parts needed to complete a specific airplane. Specialized workholding, developed over many years for legacy (older model, mature) airplanes had to fit onto the new machine, as well as new workholding needed for the latest model airplanes. Set-up time needed to be minutes, or, at most, hours and not days.

Now comes the fun part and the real challenge for my team.

The customer wanted to reduce operating costs by reducing the number of people needed to run the machines, reduce set-up time, and improve productivity. The existing machines could only manufacture small parts fitting a 20-inch x 30-inch work envelope, but the new machine had to handle these parts, plus parts as long as 240 inches. There was neither budget nor floor space to replace the existing machining centers with new ones. Between the variety of work-piece sizes and the volumes involved, this was a very daunting task. We thought about many possible solutions to the problem but kept returning to the single-machine concept.

Having developed a long X-travel, raised-carriage, fixed-bed machining center (Xi-Mill) for single or dual work-zone long-part machining, our solution was to expand the capabilities of the existing machine design by developing a new type of machine, the X-Flex Center, configured with multiple pallet receivers instead of the typical T-slot tables. This allowed the customer to load multiple workholding fixtures into the machine and have them ready to run on short notice.

Equipped with a set-up changer, the machine could quickly be reconfigured by pulling new workholding fixtures from storage and loading them into the machine to match constantly-changing production requirements and schedule changes. Having the dual work zone feature with each work zone having its own dedicated tool changer, the operator was able to load newly tooled fixtures in one zone, while parts were being machined in the other.

To meet these requirements, a zero-point clamping system was incorporated into the base table, which allowed the pallet receivers to be decked with various long-part handling special tables. The zero-point clamping features meant that different tables could be quickly installed, with a high degree of repeatability (0.0002-inch repeatability for a 120-inch-long table). Large and heavy special tables could be craned overhead, lowered into place, clamped, and locked down to do production-ready machining in minutes.

Bravo on the creation of such a complex combination of tools fitting into one machine. It reminds of today's transformers. Or, perhaps, a really cool set of legos. I really like the ability of using technology to remove the potential for human errors. Being able to control which programs can run with with tools on what tables.

It reminds me of some of the plastic tooling houses I have worked with. In order to prevent the opportunity for human error when different plastic tools are loaded into molding machines they require manifolds on all of their tools. One hot line hook-up and one cold line hook-up. Not necessarily new technology. And definitely not as cool as the set-up described in this article. But another way to minimize the chance of humans hooking something up wrong.

Bravo on the creation of such a complex combination of tools fitting into one machine. It reminds of today's transformers. Or, perhaps, a really cool set of legos. I really like the ability of using technology to remove the potential for human errors. Being able to control which programs can run with with tools on what tables.

It reminds me of some of the plastic tooling houses I have worked with. In order to prevent the opportunity for human error when different plastic tools are loaded into molding machines they require manifolds on all of their tools. One hot line hook-up and one cold line hook-up. Not necessarily new technology. And definitely not as cool as the set-up described in this article. But another way to minimize the chance of humans hooking something up wrong.

Thanks, jmiller, for hanging in there through this very long Sherlok Ohms posting. I was concerned when this was posted that readers would be put off the the length and complexity of the post. At least in your case, that didn't seem to be a problem.

In full disclosure, we're the ad/PR agency for Bertsche, the subject of this tale.

Among all our clients, Rich Bertsche is one of the most innovative and creative engineers I've encountered in 36 years working for such fellows.

They look at a customer's problem and approach it with two essential skills...

First, they bring a wealth of experience building other machines for companies in the aerospace business, in this case, to the job.

Secondly, they put no restrictions on their thinking, other than to solve the problem in an efficient, cost-effective and practical manner.

These are traits of all great American machine builders, a tribe that represents the core of our agency.

Rich's team solved the problem, even producing some unintended positives for the customer...the identity of whom must remain a mystery, per their edict. Pretty well-known airplane company, though.

Nonetheless, this story proves many truths, one of which is that, despite all the fuzzy thinking being circulated about the impending demise of American manufacturing and the need for "reshoring", a rather ridiculous concept, when you read articles such as this one, the fact is American ingenuity and engineering expertise are still able to bring together myriad components and manufacturing technologies to solve production problems better, faster and more economically than anybody else.

We're proud to work for the Bertche bunch...and many others such talented sleuths!

In full disclosure, we're the ad/PR agency for Bertsche, the subject of this tale.

Among all our clients, Rich Bertsche is one of the most innovative and creative engineers I've encountered in 36 years working for such fellows.

They look at a customer's problem and approach it with two essential skills...

First, they bring a wealth of experience building other machines for companies in the aerospace business, in this case, to the job.

Secondly, they put no restrictions on their thinking, other than to solve the problem in an efficient, cost-effective and practical manner.

These are traits of all great American machine builders, a tribe that represents the core of our agency.

Rich's team solved the problem, even producing some unintended positives for the customer...the identity of whom must remain a mystery, per their edict. Pretty well-known airplane company, though.

Nonetheless, this story proves many truths, one of which is that, despite all the fuzzy thinking being circulated about the impending demise of American manufacturing and the need for "reshoring", a rather ridiculous concept, when you read articles such as this one, the fact is American ingenuity and engineering expertise are still able to bring together myriad components and manufacturing technologies to solve production problems better, faster and more economically than anybody else.

We're proud to work for the Bertche bunch...and many others such talented sleuths!

This "case" reads like an advertisement for a flexible machining center. This is not about an investigation or solution of a particular problem, and one of the unmentioned factors is the cost of the system. Please be careful, Design News, about what you publish as a "case," or this column will morph into ads, which are generally not as interesting to read.

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